GB2061887A - Delivering sheets - Google Patents

Description

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GB2 061 887A

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SPECIFICATION

Reproduction apparatus and method

5 This invention relates to a document reproduction apparatus and methods and particularly to 5

such apparatus having an unlimited catch tray for operating in various modes.

In reproduction machines, particularly machines for high speed, high volume reproduction runs, the production of copies by the machine can often exceed the capacity of the copy sheet storage. Many attempts have been made in the prior art to correct this problem. For example, 10 U.S. Patent 4,012,032 describes a copy sheet handling system having a copy sheet receiving 10 tray for use in operating in a non-collate mode and a plurality of collator bins for operating in the collator mode. In this system, the control senses when the non-collate tray has reached capacity and automatically directs documents to the collator bins. Similarly, if operating in the collator mode and the requirement exceeds the is stacked in the non-collate tray.

15 U.S. Patent 4,026,543 teaches a control system using a copy count, a tangent copy count, 15 and a document tracing indicator to provide automatic control for copy overflows. U.S. Patent 4,134,581 describes a system having a plurality of collator bins treated as one virtual bin and sheet feedings controlled by skipping adjacent bins if the document sets to be copied have a number of papers exceeding the capacity of a single bin. U.S. Patent 4,072,304 teaches a 20 system having a collator running in two distinct modes, in particular allowing the collator to 20

continue operation by a sheet feeding malfunction and portions of the stacks having an error are directly offset from the properly collated stacks. In the other mode, the collator feed is disengaged.

Other systems such as described in U.S. Patent 4,072,854 generally teach copy sheet 25 counting in particular to determine if copy sheets are improperly overlapped and U.S. Patent 25 4,003,569 to detect the last copy sheet in a particular run.

In these systems generally, multiple copy receipt trays or bins are required. In addition, even though a multiple or plurality of trays are in use, the trays generally have limited capacities requiring either additional control for tray switching, system shutdown or additional operator 30 intervention. 30

Other systems such as in US Patent 3,870,925 require a sorter system having two sorter sections. In particular, the control switches from one section to the next to continue a reproduction requirement. In addition, if the bins in both sections of the sorter contain copy sheets, and the job requirement has not been completed, upon removal of the copy sheets in 35 one of the sections, the reproduction machine will resume operation after having been 35

temporarily halted.

The addition of multiple bins and trays increases the cost of the components for the machine and adds complexity to the control. It would therefore be desirable to provide a reproduction system, a high volume reproduction machine having a minimum number of copy sheet receiving 40 trays and yet be able to handle high volume requirements with minimum operator intervention. 40 The present invention provides from one aspect a reproduction machine having an output tray and capable of delivering copies to the tray either as uncollated stacks or as pre-collated sets,

said machine including a mode selector for determining the modes in which copies are received in the output tray, means for setting the maximum capacity of the output tray depending upon 45 the mode selected and means for inhibiting operation of the machine upon the maximum 45

capacity of the tray being reached.

From another aspect, the invention provides a method of collecting in an output tray copies from a reproduction machine capable of delivering copies either as uncollated stacks or as precollated sets, comprising the steps of 50 starting the machine to deliver copies to the tray in the selected mode, and 50

inhibiting operation of the machine when one or either of preset output tray maximum limits has been reached, depending upon the mode selected.

A preferred embodiment of a reproduction machine according to the invention has a single output catch tray and is capable of operating in stacks, unstapled sets or stapled sets modes, 55 the sets and stacks being offset in the catch tray. In the various modes of operation, the 55

reproduction machine will temporarily halt upon the output tray reaching predetermined capacities depending upon the mode of operation. However, upon emptying the contents of the output tray, the machine will resume operation and continue to do so as the tray is emptied until the completion of the requirement or until the job in process is cancelled.

60 In order that the invention may be more readily understood, reference will now be made to 60 the accompanying drawings, in which:-

Figure 7 is a block diagram of the controller for a reproduction apparatus according to the present invention;

Figure 2 is a cutaway elevational view of an exemplary reproduction apparatus incorporating 65 the control system of Fig. 1; 65

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Figure 3 is an elevational view of the recirculating document handler of the reproduction apparatus shown in Fig. 2;

Figure 4 is a detailed illustration of the operator control console shown in Fig. 2;

Figure 5 is a schematic illustration of the interconnection of the push button switches shown 5 in Fig. 4 with the controller of Fig. 1;

Figures 6 and 7 are a flow chart of the switch scan procedure of the controller disclosed in Fig. 1;

Figure 8 is a flow chart of the multitask button cascade illumination feature of the apparatus;

Figures 9 and 70 are flow charts of the message queing and duplex operation according to 10 the present invention; and

Figures 7 7 and 12 are a flow chart of the multimode unlimited catch tray feature in accordance with the present invention.

Referring to Fig. 1, there is shown a reproduction machine 10 and a controller including a ' central processor unit (CPU) module 12, input/output (I/O) module 14 and CPU interface 15 module 16. Address, data and control buses 18, 20 and 22 couple CPU module 12 and I/O module 14.

CPU interface module 16 connects the I/O module 14 with special circuits module 24, input matrix module 26 and main panel interface module 28. The CPU interface module 16 also interconnects I/O module 14 to the operating sections of the reproduction machine 10 namely, 20 input section 32, and processor section 36.

Switch and sensor inputs are provided to the CPU module 12 from the machine from either the input matrix module 26 or the main panel interface module 28 via data buses 37 and 39. A power supply 41 is also interconnected to CPU module 12 as well as to other control elements.

For a more detailed description of the control, reference is made to U.S. Patent No. 25 4,062,061.

Referring particularly to Fig. 2 of the drawings, there is shown, in schematic outline, an electrostatic reproduction machine or host machine, identified by numeral 10, incorporating the control arrangement of Fig. 1.

The machine 10 uses a photoreceptor in the form of an endless photoconductive belt 100 30 supported in generally triangular configuration by rolls 102, 104 and 106 and comprising a photoconductive layer of selenium, on a conductive substrate. Belt 100 is supported to provide substantially flat areas at exposure, developing, and cleaning stations 108, 110, 112 respectfully. The photoconductive belt 100 moves in the direction indicated by the solid line arrow, drive being provided through roll 106, in turn driven by a main drive motor (not shown). 35 Machine 10 includes a generally rectangular, horizontal transparent platen 114 on which each original or document to be copied is disposed. A two or four sided, illumination assembly 11 6, disposed below and along at least two sides of platen, is provided for illuminating the original on platen 114. The light image generated by the illumination system is projected via mirrors 118, 120 and a variable magnification lens assembly 122 onto the photoreceptor belt 40 100 at the exposure station 108. To prepare belt 100 for imaging, belt 100 is uniformly charged to a preselected level by charge corotron 124. Magnetic brush rolls 126 are provided in a developer housing 128 at developing station 110. The bottom of housing 128 forms a sump within which a supply of developing material is contained.

To transfer developed images from belt 100 to the copy sheets, a transfer roll 130 engages 45 copy sheets driven from either main or auxiliary tray 1 32, 134 by main and auxiliary sheet feeders 136, 138 respectively. Paper is generally fed from the main tray 132. Main transport 140 extends from main paper tray 1 32 to transfer roll 1 30 and is driven from the main motor. Auxiliary transport 142 extends from auxiliary tray 134 to main transport 140 and is also driven from the main motor. The image bearing sheets leaving the nip formed by photoconductive belt 50 100 and transfer 130 are picked off by vacuum transport 144 and conveyed to the fuser having a lower heated fuser roll 146 and upper pressure roll 148.

The reproduction machine 10 also includes a recirculating document handler (RDH) shown generally at 1 50 and a finishing station shown generally at 152. The recirculating document handler 150 shown in detail in Fig. 3 feeds originals automatically onto platen 114 from tray 55 154. The machine 10 can make multiple collated sets of originals by successively feeding to and removing originals from the platen 114. A manual input station is also provided to place an original on the platen 114.

The finisher 152 contains a compiler tray 156, a stapler 158 and an offsetting catch tray 160. In the non-collation or stacks mode, successive, identical copy sheets are fed directly 60 through the finisher 152 to the offsetting catch-tray 160. In the collation (RDH) or sets mode, successive, non-identical copy sheets are fed into the compiler tray 156 and compiled until the completion of the set. At this time the set is stapled or not stapled as required, and ejected to the offsetting catch-tray 160. The offsetting catch-tray 160 offsets between successive sets to maintain set integrity. A list of possible combinations between document input, copy, and 65 output format is shown in Table I.

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TABLE I

LIST OF AVAILABLE MODE COMBINATIONS

Document Input

Copy

Offset Outputs

Manual Platen

1/Sided

Copy/Main Fd

Stacks

Manual Platen

1 /Sided

Copy/Aux Fd

Stacks

Auto

Feed/1

Sided

Doc

1 /Sided

Copy/Main Fd

Sets

Auto

Feed/1

Sided

Doc

1 /Sided

Copy/Main Fd

Stapled

Sets

Auto

Feed/1

Sided

Doc

1 /Sided

Copy/Aux Fd

Sets

Auto

Feed/1

Sided

Doc

1 /Sided

Copy/Aux Fd

Stapled

Sets

Auto

Feed/1

Sided

Doc

2/Sided

Copy/Main Fd

Sets

Auto

Feed/1

Sided

Doc

2/Sided

Copy/Main Fd

Stapled

Sets

Auto

Feed/1

Sided

Doc

2/Sided

Copy/Aux Fd

Sets

Auto

Feed/1

Sided

Doc

2/Sided

Copy/Aux Fd

Stapled

Sets

Auto

Feed/2

Sided

Doc

2/Sided

Copy/Main Fd

Sets

Auto

Feed/2

Sided

Doc

2/Sided

Copy/Main Fd

Stapled

Sets

Auto

Feed/2

Sided

Doc

2/Sided

Copy/Aux Fd

Sets

Auto

Feed/2

Sided

Doc

2/Sided

Copy/Aux Fd

Stapled

Sets

Auto

Feed/1

Sided

Doc

1 /Sided

Copy/Main Fd

Stacks

Auto

Feed/1

Sided

Doc

1 /Sided

Copy/Aux Fd

Stacks

10

15

"20

25

With reference to Figs. 3 and 4 for the RDH 150 mode and one sided documents and copies, the operator programs the machine and places the originals in the RDH tray 1 54 face up (1 to N).

Documents are driven one at a time in N to 1 sequence from the bottom of the set in tray 30 154 by feeder belt 166 to tray takeaway rollers 168 leading via curved guide 170 to platen entry rollers 172 which drive the document into engagement with platen belt 1 74 for. movement onto platen 114 into synchronism with the movement of the preceding document off platen 114.

After exposure, documents are driven off platen 114 by platen belt 174 into engagement 35 with return transport rollers 1 76. The documents are conveyed to middle rollers 1 78 to tray entry rollers 180 for return to tray 1 54. The reproduction machine develops and delivers each copy in sequence face up to the catch tray 160. Complete sets of N copies each are offset in tray 160 and if the staple mode is selected the sets are stapled.

For one sided originals/two sided copies, in the first pass, the operator places the document 40 in the RDH tray 1 54 face up in reverse order and presses Print. The RDH advances each original in sequence and the even originals are flashed in (2-N) sequence. If the set has an odd number of pages, the machine processor passes a blank sheet at the end of each set. There is no precount of documents by the RDH and there is one flash per two document feeds. The machine processor feeds a copy every other pitch or copy cycle. Skipped pitches are faded out 45 with a pitch fadeout lamp. The copies are delivered to output tray 1 60 face up in descending order. That is

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The blank sheet is not billed and the tray 160 does not offset the set. Stapling, if selected, is inhibited during this pass. In the second pass, the operator removes the documents and reorders them into the original order, loads the RDH tray 1 54, moves the half-copies to the auxiliary feed tray 1 34 and presses Print. The RDH 1 50 operation is the same as first pass except odd 55 documents are flashed (N-1). Again there is one flash per two feeds. The one "side or half-copies are then conveyed from feed tray 1 34 via transport 142 to transfer roll 1 30 to receive a second side image. The machine processor operation is the same as the first pass except copies in the output tray 160 are in the correct order and the sets are offset. If selected, stapling of the sets is accomplished at this time. That is, the copy sheets for one complete set are accumulated in 60 compiler tray 1 56, stapled and then ejected to the catch tray 1 60.

For the RDH 1 50 mode and two sided orginals/two sided copies, in the first pass, the operator places the documents face down in RDH tray and presses Start. The RDH advances each document in 1-N sequence and flashes the back side of each document once per copy. There is one flash per feed. The machine processor develops and delivers each copy in sequence 65 to the output tray 1 60 with one pitch skipped between sets. There is no offset of copies nor

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stapling. In the second pass, the operator flips the stack of documents over in the RDH tray 1 54, moves the half-copies from the output tray 160 to the auxiliary feed tray 134, and presses Start. The RDH operates the same as first pass except front sides are flashed in (N-1) sequence (one flash/feed). The machine processor operation is the same as first pass except copies are in 5 correct order and the sets are offset in the output tray, and if selected, the sets are stapled. 5

For the RDH mode of operation and stacked or uncollated copies, the operator places the documents face up in the RDH, programs the machine and presses Start. The machine makes the total quantity of copies programmed of the bottom document, delivers them to output tray 160 (does not compile) and shifts the tray after the last copy of each document is delivered. The 10 RDH 150 indexes to the next document and resumes copying. The job output is offset stacks. 10 For manual operation, the operator places the document or book on platen 114 and presses Start. The machine makes the required copies, stacks them directly in the output tray 1 60 (not compiled), stops, shifts the tray and displays Ready.

With reference to Figs. 4 and 5 there is shown the operator's control console 262 including 1 5 varius inputs switches and indicator lamps. The interconnection of these switches and the main 1 5 panel interface module 28, the input matrix module 26 and the CPU module 12 are illustrated ? in Fig. 5. Of course all connections to the CPU module are through the input/output module 14.

The console switches are continuously monitored by a switch scan procedure to initiate the 20 correct operation for a particular combination of switch inputs. The inputs from the twenty 20

console switches are arranged into three bytes of information as set forth below in Table II.

TABLE II BIT POSITIONS

25

30

D7

D6

D5

D4

D3

D2

D1

DO

Keyd

Bit

Bit

Bit

Bit

Bit

Bit

Bit

Bit

Byte 1

1

2

3

4

5

6

7

8

Keybd

Bit

Bit

Bit

Bit

Bit

Bit

Bit

Bit

Byte 2

9

0

Un-

Clear

Serv.

Start

Stop

Marked

Key

Print

Print

Keybd

Out-

Paper

Copy

Copy

Reduc

Byte 3

Put

Tray

Contrast

Mode tion

25

30

35

40 The switch scan procedure is shown in the flow charts of Figs. 6 and 7. In particular, the scan 40 is made every 20 milliseconds and in an effort to filter out noise, two readings of the byte are taken approximately 13 microseconds apart. If they are the same, a third reading is not required. If they are not the same, the result of a third reading taken approximately 13 microseconds later is used.

45 The machine is generally operating in one of eight different states namely an initialization, 45 lamp test, run not print, print, ready, not ready, tech rep, and component control states. The system can be executing in only one state at a time. The system operates in a state until it recognizes a condition requiring a state change. *

The initialization state is completed after a system self-test or system self diagnostics and in 50 this state various flags and data are set to initial values required for system operation. In 50

accordance with one feature of the present invention, the system enters the lamp test state and in this state turns on all front panel lights and indicates 8888 on the digital display 164 for an automatic lamp test feature. There is a short, approximately 5 seconds, display of all the front console lamps. Xhis occurs shortly after power is turned on. This provides an indication to the 55 operator of any burned out or otherwise inoperative display components. This also eliminates 55 the need for a button to request the display. It should also be understood that as machine performance is monitored over a history of use, various changes are often required to the systems software to optimize operation. Generally these changes are made in various stages. Therefore for diagnostic and evaluation purposes it is often desirable to know the particular 60 stage or level of software in the system. This information is available in the digit display 164 60 during this period of lamp tests by keying the unmarked push button 166 on the operator's console. A coded display will indicate the level of software in the system.

After the lamp test state, the system, at the expiration of the 5 seconds, enters the not ready state. There are approximately 11 conditions that must be satisfied before the system changes 65 from the not ready to the ready state. For example, the lens selection must equal the lens 65

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position switch, that is, the lens must not be in motion, the bottom and top trays if selected must have enough paper, the fuser must be up to temperature, all stand by interlocks must be closed, the fuser must not be over-temperature, the photoreceptor belt must not be mistracked, all fault codes must be cleared, if RDH is selected it must not be in a jam condition, the offset 5 catch tray 160 must not be full or the capacity cannot be exceeded, and the offset catch tray 5 160 must be emptied if two sided copy mode is selected.

The system next enters the ready state upon satisfying the not ready conditions and then is ready to enter the print state. From the ready state the system will normally go either to the print state back to the not ready state or to the tech rep state if required. Upon activation of the 10 print button the system enters the print state. Upon completion of the reproduction run, or upon 10 encountering a machine malfunction, the system exits from the print state to a run/not print state. After the completion of this state there is entered a not ready state.

The tech rep state is entered when the service key is on, the system is in not ready or ready state, and the display select and clear buttons are depressed simultaneously. This allows the 15 tech rep to access programs not otherwise available, such as diagnostic programs. 15

k In the various states, except the initialization state and the tech rep states, the machine or controller is generally performing housekeeping and systems operations. There are also provided a priority of interrupts to alert the controller of the reproduction machine events and requirements and to synchronize the controller and the reproduction machine. The events and 20 requirements of the reproduction machine 10 generally require high speed response and to 20

facilitate the response a multiple interrupts system is provided.

There are two external interrupts in particular a pitch reset interrupt and a machine clock interrupt. The pitch reset is the highest priority interrupt and is generated by a not shown reset switch synchronous with potential copy sheet registration in the reproduction machine. The 25 interrupt initiates the resetting of various clocks and timed events for correctly operating on 25

images and copy sheets in various stages in the process. The interrupt occurs only while the main motor is running and normally at a frequency of 1.25 Hz.

The second level of interrupt is the machine clock interrupt and is initated by the machine clock pulses generated by a not shown magnetic pickup on the main drive motor. It performs 30 the functions of scheduling and controlling events in synchronization during the print state and 30 schedules and controls register output data to the reproduction machine components during all states of operation. A third interrupt, although a non-external interrupt, is a real time clock interrupt. This is the lowest priority interrupt used and the clock signals are produced by the controller clock to decrement several uniquely assigned memory cells at predetermined intervals. 35 For a more detailed discussion of the overall operation of the controller, reference is again made 35 to U.S. Patent No. 4,062,061, incorporated herein.

In accordance with the present invention, the control console 262 is generally organized into signal push button cascaded displays. For example, the reproduction machine 10 in normal operation will produce full size copies unless the "reduction" button 268 is pressed. In other 40 words, in system ready at start up, the lens 1 22 is in position for full size copying and the full 40 size lamp 270 on console 262 is illuminated. However, upon actuation of the reduction button 268, the lens 122 will next position itself for 98% reduction with the corresponding lamp 272 illuminated. The next activation of the reduction buttom 268 will initiate the movement of the lens to the 74% reduction position with the corresponding lamp 274 illuminated, and similarly 45 the system is moved to the 65% reduction and lamp 276 illuminated upon activation of button 45 268. The next activation of button 268 will return to a full size illumination.

Similarly, the operator may select normal, dark, or light output by successive actuation of the copy push button. As described, the successive pressing of push button 278 causes the controller to acknowledge by illuminating appropriate lamps and stepping from one selection to 50 another in a wrap-around sequence. This stepping operation is allowable even while the system 50 is making copies. However, the controller performs an immediate response and also set up a deferred action. In other words, the immediate task, that is the stepping of the Illuminated lamps occurs immediately to provide operator feedback. The deferred action, for example, is the movement of the lens or adjustment of the developer bias and adjustment of the lens iris 55 opening for darker or lighter copies. The deferred action will be performed if there are no 55

additional button actuations within a certain time period, for example, approximately 1 second. The delay is necessary to prevent needless dithering of the controller until the correct mode has been selected.

The multi-task button, cascade illumination feature is further described with respect to the 60 reduction operation with reference to Fig. 8. In particular, the reduction operation is determined 60 by the count in a reduction state counter (Rd STATE). Counts of zero, one, two, and three correspond to no reduction, 98% reduction, 74% reduction and 65% reduction respectively. The counter is incremented in response to successive actuations of the reduction push button 268, with an initial state of zero or no reduction before any activation of the push button. 65 The sequence is merely to increment the counter in response to activations of the push button 65

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268. In Fig. 8, the first decision block is to determine if the counter is greater than three, and if so to reset the counter to zero. The contents of the counter are then scanned and for a particular counter number a particular reduction mode is initiated. The switch scan is constantly monitoring the various switches in the machine and checking for changes caused by switch 5 actuation. 5

As an example of reduction, assume that the counter is in the zero state and the reduction button is keyed twice for a 74% reduction. The activation of the button will be detected by the main panel interface module 28 and the input matrix module 26. The CPU module 12 will recognize the mode selected and set an appropriate flag, in this case, the 74% reduction flag 10 and illuminate lamp 274. While this operation is being executed, the switch scan routine will 10 continue to monitor the various switches for the possibility of a new mode selected or the 74% reduction having been cleared. If it is determined that the 74% reduction remains selected, the lamp 274 remains illuminated and it is determined that a new lens position is required. A determination is made of the current position of the lens and the lens drive motor is activated to 1 5 drive the lens to the appropriate 74% reduction position. At the appropriate position, the wait 1 5 light is turned off and the ready light turned on. s

As shown in Fig. 4, the control console 262 includes ten selectively illuminated lighted displays to assist the operator in operating the reproduction machine. In particular, the messages are Close Bottom Paper Tray Door, Sets Too Thick To Staple, Unload Top Paper Tray, 20 Add Paper, First Page Bottom Last Page Top, Last Page Bottom First Page Top, Originals Face 20 Up, Originals Face Down, Unload Output Tray, and Load Copies In Top Tray. Most of these messages are primarily used in guide the operator through the process of making duplex copies in either a simplex to duplex or duplex to duplex mode. Some are used for other instructional purposes.

25 Although these messages are normally displayed in predetermined sequences or queues, the 25 operator may perform operations appropriate to the duplex mode chosen in different or alternative order. In this case, queuing or sequence of the messages will adapt to the order of operator activity or performance. In any case, the queuing message is displayed or illuminated until the sensors detect that the appropriate action has been taken.

30 In other words, it is desirable to guide the operator with a limited number of messages at a 30 time and to guide the operator in a step by step sequence. However, it is not necessary to follow the messages exactly. If the operator has already covered a particular step, it is skipped in the sequence of messages. The steps can be covered in any order as long as all necessary steps are completed for the next operation.

35 The operator is guided by appropriate bacidit instructions as illustrated with reference to the 35 flow chart shown in Figs. 9 and 10. In particular, assume that the operator requires a single side document two sided copies mode. The operator will press the "Copy" button once to change from one side copies to two sided copies.

The procedure referred to as "Pass 1", shown in Fig. 9 initially checks whether or not the 40 output or catch tray 160 and upper (top) tray or auxiliary feed tray 134 are empty. If there is 40 paper in the output or catch tray 160, the operator is instructed by the illuminated message "Unload Output Tray" on the control panel 262 to unload the output tray 160. Once the copies are unloaded the message lamp is turned off. The upper paper tray (auxiliary feed tray) 134 is also checked and if there is paper in the upper paper tray 134, the operator is instructed by the 45 message "Unload Upper Paper Tray" to unload the upper paper tray (auxiliary feed tray) 1 34. 45 Once the sheets have been removed from the upper paper tray 160, the message lamp is turned off as with the output tray message.

It should be noted that if the upper paper tray 134 has been selected for feeding paper, the 4 "Unload Upper Paper Tray" message will not be illuminated and the operator will not be 50 instructed to unload the upper paper tray. Another check is also made to determine if there are 50 documents in the RDH.

Assuming the output and upper trays are empty, two more messages are illuminated in an on-off or blinking manner, in particular the "First Page Bottom, Last Page Top" message and the "Originals Face Up" message.

55 "The First Page Bottom, Last Page Top" and "Originals Face Up" messages (RDH load 55

instructions) instruct the operator on how to place the documents to be copied in the RDH. The system will then monitor that there are documents in the RDH and it is assumed that the documents are in fact in the correct format. The RDH load instructions then remain on in a steady state. At this point the Ready lamp is illuminated if all conditions for ready are met and 60 the operator activates Start Print. The machine then runs the first pass, that is copies the even 60 numbered documents and delivers the copies to the output tray 160 for as many sets as required up to the tray capacity. At this point there is no offset of the sets nor any stapling. If the run length should cause the pass "1" copies to exceed the capacity of the output tray, the job is automatically broken up into tray-sized segments, each with a "Pass 1-Pass 2" sequence 65 until the full job is completed or cancelled by the operator. 65

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At the completion of the first pass, the system enters into the pass "2" sequence as illustrated in Fig. 10. In particular, the Ready lamp goes off and if the upper tray 134 has not been previously selected, it is automatically selected at this point by the controller. This is necessary because the side one copies will be loaded into and fed from the upper paper or 5 auxiliary feed tray 134. At this time also ail the duplex message lamps will be turned off. The 5 "Unload Output Tray" message and the "Load Copies in Upper Tray" message will then be illuminated. Once the operator empties the output tray 160, the "Unload Output Tray" message will shut off and as soon as the operator loads the side one copies into the upper tray 134, the "Load Copies in Upper Tray" will be turned off.

10 The "Last Page Bottom, First Page Top" message and the "Original Face Up" message (RDH 10 load instructions) will then be illuminated on the control console. This instructs the operator on how to reposition the documents in the RDH. Once the documents have been removed and replaced, it is assumed that the documents are in the correct order and the ready lamp is illuminated for another print cycle. If the documents have not been removed and replaced, the 15 RDH load instruction messages that is the messages relating to RDH operation, will flash in an 15 on-off manner. Once removed and replaced, however, the RDH load instruction remain on in a steady condition and the machine completes the duplex operation.

The operation is similar for a duplex to duplex operation except instead of the "Original Face Up" message there is an "Original Face Down" message for pass 1. For pass 2, the "Original 20 Face Up" message will be illuminated for RDH operation, operation instruction. 20

With respect to Fig. 2, there is shown the finisher area 152. In particular, there is a post fuser turnaround transport 210, a pre-registration transport 212, a compiler tray 156, a stapler 158, and the output or offsetting catch tray 160. Also included are compiler entrance and exit switches illustrated at 216 and 218, an offset catch tray out of paper and position sensor 270, 25 and a catch tray position motor (not shown). 25

The finisher module 1 52 receives fused copies from the turnaround transport 210 for reversing the direction of paper travel and delivering to the preregistration transport 212. The preregistration transport 212 ensures proper side registration for different size papers for proper staple location. Depending upon selection, stapled and collated sets can be provided by the 30 stapler. A scuffer assembly (not shown) is located at the rear of the compiler tray 156 and is 30 used for fine set registration and sheet ejection. The sheets scheduled for collating are.captured in the tray 156 by two not shown plastic tabs called registration gate fingers. These gate fingers are down in the uncollated or stacks mode in order not to capture copies.

In accordance with the present invention, the offset catch tray sensor 270 monitors sheets left 35 in the tray from a previous job. It will also signal Unload Tray if an operator selects duplex 35

copying or, if the number of sheets or sets exceeds a maximum capacity, a machine cycle down will be initiated. The cycle down is approximately ten seconds longer than normal to enable the operator to unload the tray. If the job programmed was incomplete, unloading the tray will cause the Print cycle to resume.

40 The offsetting catch tray or output tray 1 60 is limited in capacity and can fill to the point of 40 causing jams. The point of jam can vary depending upon whether there are stapled sets, non-stabled sets or stacks being produced. In accordance with the present invention, the sensor 270 is provided along with the "Unload Output Tray" message to prevent the occurrence of jams and yet allow the reproduction machine to complete high volume requirements. In particular, 45 variable parameters are set in the non-volatile memory to be able to control the capacity of the 45 output tray 160. In response to reaching a predetermined boundary for either stapled sets,

unstapled sets or stacks, the system is shut down. However, if the tray is emptied during operation, the machine will restart and continue on with the operation.

In particular for limitless tray operation, the tray 160 capacity is controlled by an internal 50 counter keeping track of both sets and copy sheets delivered. Reset of the counter occurs only 50 when the tray is unloaded. In one embodiment a capacity of 40 sets and 350 sheets is set. The limits or tray boundaries held in non-volatile memory are service representative modifiable about a nominal capacity.

For the stapled sets mode, upon counting 40 stapled sets in the output tray, or the total sheet 55 count exceeds 350, the machine lights "Unload Output Tray" and stops making copies for 55

approximately 10 seconds, while the machine processor continues to run. When the tray is unloaded, the machine automatically restarts and resumes copying. For unstapled sets,

operation is the same as above except only sheet count 350 (not set count) limits capacity;

shutdown starts at the end of the set in process in this mode. In the uncollated mode, the 60 capacity is also 350 sheets. For a series of shorter jobs, the counts of stapled sets and sheets 60 are accumulated and reaching either of the limits starts a shutdown sequence. If the tray is not unloaded within 2 minutes, a 2 minute timeout occurs and the Start button must be pressed to resume operation.

This operation is illustrated with respect to the flow chart shown in Figs. 11 and 12. The 65 general function of the procedure is to monitor the output tray 160 capacity. If the tray 65

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becomes full during a run according to set boundaries, the machine will be cycled down until the tray is emptied and then automatically restarted if the job is incomplete.

In particular, the first decision blocks determine if sheets are in the output tray 1 60 and the second decision block determines if the system is in Pass '1" of a duplex operation. No sheets 5 in the output tray indicates, for example, that the tray has been unloaded. Therefore, if the 5

system is not in Pass "1" duplex, print cycle, is resumed, the Unload Output Tray message is turned off and the set and copy counters are reset.

The next decision block determines if the output tray 160 was actually full when emptied.

That is, a determination is made on the tray having reached limits before unloading. If so, a tray 10 full flag is cleared and the next decision block is print cycle or cycle down. If the tray was not at 10 capacity when emptied, there is an immediate step to the print cycle or cycle down decision block. This decision block is also reached immediately if there are sheets in the output tray 160 or if there are no sheets in the output tray, but the system is in Pass 1 of the duplex operation.

- If in Pass 1, it is preferable not to reset the counters and enable print cycle even if the output 1 5 tray has been emptied. This procedure allows for duplex set integrity when the tray is unloaded 1 5 before reaching tray capacity. „

If there are sheets in the output tray 1 60, delivery of sheets is acknowledged before the print state or cycle down decision block is reached.

If the system is in print state or cycle down, the tray limits are checked. That is, the capacity , 20 of the catch tray 160 is checked against an unstapled sheet limit (300 in a particular 20

embodiment). If the limit has been reached, a flag or indication of full capacity will be made,

that is, the Unload Output Tray message indicated by the set flag output tray full block. If the sheet limit has not been reached, the set limit will be checked if the system is in the stapled sets mode (40 in a particular embodiment). If the 40 limit has been reached the system will again 25 indicate full tray capacity. If the limits have not been reached, the system will return to the 25

"sheets in output tray 160" decision block, acknowledge deliveries and repeat the limit checking procedure. If there is tray capacity, the system will resume operation upon unloading of the catch tray 1 60 within a specified time limit.

Claims (8)

30 CLAIMS 30

1. A reproduction machine having an output tray and capable of delivering copies to the tray either as uncollated stacks or as pre-collated sets, said machine including a mode selector for determining the modes in which copies are received in the output tray, means for setting the maximum capacity of the output tray depending upon the mode selected and means for

35 inhibiting operation of the machine upon the maximum capacity of the tray being reached. 35

2. A reproduction machine according to claim 1, wherein the machine automatically resumes operation upon unloading of the output tray.

3. A reproduction machine according to claim 1, wherein the machine automatically resumes operation upon unloading of the output tray within a predetermined period of time.

40

4. A reproduction machine according to claim 3, wherein the predetermined period of time 40 is two minutes.

5. A reproduction machine according to any preceding claim including means for stapling pre-collated sets as that the output tray may receive copies as stacks or stapled or unstapled sets and the capacity for stack and unstaples set modes is a predetermined number of copies, the

45 capacity for stapled sets being limited to said predetermined number of copies or a predeter- 45 mined number of sets.

6. A method of collecting in an output tray copies from a reproduction machine capable of delivering copies either as uncollated stacks or as pre-collated sets, comprising the steps of s selecting the mode in which the copies are to be delivered to the tray,

50 starting the machine to deliver copies to the tray in the selected mode, and 50

inhibiting operation of the machine when one or either of preset output tray maximum limits has been reached, depending upon the mode selected.

7. A method according to claim 6, including the steps of unloading the output tray, and resuming operation in the mode selected.

55

8. A method according to claim 6 or 7, including the optional step of stapling sets, in which 55 in stack mode or unstapled sets mode the tray capacity is limited by number of copies and in which in stapled set mode the tray capacity is limited by either of number of sets or said number of copies.

Printed for Her Majesty's Stationery Office by Burgess & Son (Abingdon) Ltd.—1981.

Published at The Patent Office, 25 Southampton Buildings, London, WC2A 1 AY, from which copies may be obtained.